In an interview with police, Heap said he had been put under pressure, although he had not been threatened directly, by a prisoner who he refused to name.

Detective Chief Inspector Chris Mossop, head of the Titan prison corruption unit, said: “This sentence is a message to those prison staff who are considering taking contraband into prison.

“Titan continues to set dismantling prison corruption as a priority and with staff dedicated to investigating prison staff suspected of being involved in the supply of drugs and contraband within prisons, if they are convicted they will be looking at similar lengths of sentence.”